Bottling lines are known which comprise a plurality of units for carrying out respective operations on containers.
Very briefly, the known bottling lines comprise a rinsing unit for rinsing containers, a filling unit for filling containers with a pourable food product, a capping unit for capping the containers, and a packaging unit for packaging together a given number of containers so as to form a plurality of groups of containers.
The bottling line comprises an end station fed with groups of containers travelling on one or more rows on a horizontal conveyor along a horizontal direction.
In particular, the end station comprises a unit for forming batches of groups of containers.
The above unit is, in particular, adapted to separate a plurality of batches of groups of container of a given length along the direction from the remaining groups and to form a layer of groups of containers.
An example of end station is shown, for example, in U.S. Pat. No. 7,896,151.
The above unit substantially comprises: a distribution belt which receives a plurality of containers in abutting relationship with each other; a conveyor belt for forming a plurality of batches separated by a gap from the containers conveyed by distribution belt; and a forming belt where manipulating means, e.g. a plurality of robots, form a layer of the previously formed batches which will be part of a pallet.
Furthermore, the end unit comprises: a first motor for driving the distribution belt; a second motor for driving the conveyor belt; and a third motor for driving the forming belt.
In detail the first motor and the second motor drive the distribution belt and the conveyor belt respectively at different speeds in order to allow the separation of the batches onto the conveyor belt from the groups still travelling on the distribution belt.
Still more precisely, the first motor intermittently accelerates the first conveyor, moves it at a constant speed and decelerates the first conveyor until the latter stops.
The second motor drives the conveyor belt at a constant speed.
When the end station is fed with two or more rows of groups of containers, a need is felt within the industry to increase the throughput of the unit.
In greater detail, a need is felt within the industry to avoid that the inevitable misalignment between the rows of groups penalizes the operation of the manipulating means.
Furthermore, a need is felt to avoid that the above-mentioned inevitable misalignments amplify and propagate over time with the operation of the unit.